Advancing on Saddam Hussein’s hub of power, coalition planes and helicopters pummeled Iraqi Republican Guard forces just south of Baghdad Monday as ground forces got to about 50 miles within the capital city in the midst of blinding sandstorms.

"Coalition forces are closing in on Baghdad," Maj. Gen. Stanley McChrystal of the Joint Staff Operations said Monday.

Citing U.S. officials, CBS News reported that the Republican Guard had been authorized to use chemical weapons on coalition troops once they crossed a red line that Iraqi leadership had drawn around Baghdad. The report was unconfirmed.